TRANSCRIPTIONAL REGULATION OF MUSCLE FATTY-ACID-BINDING PROTEIN

Heart fatty acid-binding protein (H-FABP) is present in a wide variety of tissues but is found in the highest concentration in cardiac and r ed skeletal muscle. It has been proposed that the expression of H-FABP correlates directly with the fatty acid-oxidative capacity of the tis sue. In the present study, the expression of H-FABP was measured in re d and white skeletal muscle under two conditions in which fatty acid u tilization is known to be increased: streptozotocin-induced diabetes a nd fasting. Protein concentration, mRNA concentration and transcriptio n rate were measured under both conditions. The level of both protein and mRNA increased approximately 2-fold under each condition. The tran scription rate was higher in red skeletal muscle than in white muscle, was increased 2-fold during fasting, but was unchanged by streptozoto cin-induced diabetes. In addition to supporting the hypothesis that H- FABP is induced during conditions of increased fatty acid utilization, these findings demonstrate that the regulation of H-FABP expression m ay or may not be at the level of transcription depending on the stimul us.